1. Field of the Invention
This invention relates to improvements in the construction of the disc screen conveyor rotors and in the drive arrangement for rotary disc screen conveyor apparatus.
2. Description of the Prior Art
An example of the prior art is seen in U.S. Pat. No. 4,452,694 of June 5, 1984 where a common drive for the several shafts comprises a chain engaged with sprockets on each shaft so that the power input from a single electric motor is connected to all of the shafts. The shafts support disc members that interleave between shafts to form openings between adjacent discs for the passage of material which is small enough to drop through. Such prior art apparatus is seen in U.S. Pat. No. 4,301,930 of Nov. 24, 1981. A further example of a rotary disc screen apparatus is seen in my prior patent U.S. Pat. No. 4,658,964 of Apr. 21, 1987.
Rotary disc screen apparatus is employed for handling a variety of material where the intent is to separate small components from components having large surfaces for effecting a sortation process to remove small size components from larger components.
A problem with prior rotary disc screen apparatus is that the construction of the shafts and discs do not allow for easy or rapid changing the discs or the spacing between discs, as it is frequently necessary to adapt the screen to a variety of material to obtain a larger or smaller size of components capable of passing through the screen. Currently, the rotary disc screen apparatus is practically adapted for one type of material, and if it is a requirement to be able to interchangeably handle a variety of material for screening out components having different size requirements the shafts and discs must be dismantled in order to install different discs for such different materials.
A further problem with the current types of rotary disc screen apparatus is that a single drive motor is provided to drive a substantial number of shafts or a series of shafts. When a jam occurs between discs of adjacent shafts, the torque provided from a common drive motor has been found to be insufficient to overcome such a jam. Accordingly, the motor needs to be reversed to free up the jam, and that interrupts the output of the material being screened.